Cycles / CUDA Error: Out of Memory
The short answer is that SSS on the GPU eats up a lot of memory, so much so that it is recommended to have more than 1 GB of memory on for your GPU. This was mentioned in one of the videos from the Blender Conference (unfortunately I can't remember which one). Updating your drivers won't really help as that can't add more memory, so for now you are stuck with having to render on the CPU. If you have multiple objects that have SSS shaders on them then you could try just rendering one at a time and then compositing them back together.